1. Field of the Invention
The embodiments of the invention generally relate to electronic fuses (e-fuses) and, more specifically, to embodiments of a circuit structure for programming and re-programming a low power, multiple states, e-fuse and an associated method for programming and re-programming such an e-fuse.
2. Description of the Related Art
Programmable fuses or anti-fuses, e.g., electrical or laser fuses or anti-fuses, are critical for modem integrated circuit applications to achieve redundant, reusable and reliable design. Unfortunately, most such programmable fuses or anti-fuses can be programmed only once. That is, they are destructive in nature so that re-programming is impossible. For example, when a conventional electronic fuse is programmed (i.e., blown), an open state is created that can not be reversed. Similarly, when a conventional anti-fuse is programmed, a short state is created that can not be reversed. Non-volatile random access memory (NVRAM) uses a floating gate scheme that is capable of reprogramming many times and can be incorporated into circuit designs for programming functions in place of programmable fuses. However, the use of NVRAM technology significantly increases process complexity and manufacturing costs. Therefore, it would be advantageous to provide a low power, multiple states e-fuse that can be more easily incorporated into existing processes and where the programming is non-destructive in nature, along with a circuit structure for performing the programming and re-programming, and an associated method for programming and re-programming such an e-fuse.